Bake oven



' July" 26, 1927. 1,636,795

P. AHLHEIM BAKE OVEN Fi led April 11, 1923 3 shoqts sheot 1 Patented July 26, 19279 UNITE!) STATES PETER AHLHEIM, OF ST. LOUIS, MISSOURI.

BAKE OVEN.

Application filed April 11, 1923. Serial at. 631,288.

4 My invention relates to improvements in bake ovens and has for its primary object a bake oven for use in bake shops which is so constructed as to evenly distribute the heat and prevent the formation of eddy-currents. which currents result in uneven; heating of the ovens or in other words, the formation of hot and cold spots. H g

A further object to construct a bake oi'enin whichthe heating'fliies can be practically hermetically sealed after the oven ha's been heated thereby preventingcold air from entering and chilling the oven.

A; still further object is to construct a bake oven which has no grate and ,in which various fuels such as coal. coke, wood. fuel oil or: gas can be used;

In the. drawings; V

Fig. 1 isfanelevation of a bake oveirenr bodying my invention viewing the same fronithe baking side;

.Fig. 2 is an elevation of the same viewed from the firingside; V

Fig. 3 is a vertical cross section taken on a line 3-3 of Fig; l'viewing same in the direction of the arrow; H H 1 .Fig. his a vertical section taken on a line 1-40f Fig. 3 p v Fig. 5 is a horizontal section taken on the line 55 of Fig 2;

Fig. 6 is a" fragmeiital vertical section taken through the furnace showing my device equipped with gas or oil and Fig; 7 is a perspective view of the door madeuse of in Fig. p I g In carrying out my invention Iemploy a casing 7' which ispreferably constructedfof brick, this casing has side and end walls, the lower part of the casing is built up in the form of a hollow rectangle which is pro.

vided with afilling 8, this fillingis prefer ably of cinders or other similarcheap material which will readily absoro heat, over the filling 8 and fo'rmed integral with the walls is a layer of brick work 9, on this layer of brick are built walls 10 which divide the space above the brick work 9 into heating furnaces 11, these walls. are connected togethei" by means of arches 12. The brick work9 will hereafter be termed thefioor of the heating chamber; extending from the floor 9 to the arches 12 are walls 13 and divide the rearpm of the heating chamber into passages 14, these passages terminate in alaterally extendingvertical flue 15, the width of this flue is equal to the combined widths of dues 14-. and walls 10 and 13 so as to provide an unobstructed passage for the tire gases and other products of combustion. Upon the arches12 is placed a filling 16, this filling is preferably a mixture of cinders, broken glass and sand, as this is a substance or combination thereof which absorbs and retains a great amount of heat but will gradually allow it to radiate therefrom; on top of the filling 16 is placed a layer of brick 17 which forms the floor of the bake oven 18',

spaced above the floor 17 is a top or roof 19 which extends over the bake oven. On this roof are placed tiles v or bricks 20 which divide the space above the roof 19 into a plurality of flues 21, these flues open at one end into the vertical flue andterininate at the other end in a laterally extending hori-. zontal flue 22, vand into which all the flues'21 open, the horizontal'flue also opens into the chimney 23 On top of the bricks or tiles is placed a layer of tile 2 1 which forms the roof of the fines 21 and on top of this roof is v placed a layer of sand 25 which tendsto conserve the heat. The chimney 23 is provided with a damper 26. which is adapted to be moved in or out so as to open or close the passage in the chimney, it is also for the purpose of regulating the draft. Communieating with the flue 22 are passageways 27 which extend through the wall and are opposite the fiues 21, these passages are forthe purpose of cleaning the lines 21 and 22 and are closed by means of doors 28. Secured in one of the walls and opening'into the heating furnaces 11 are passageways 29, these are for the purpose of introducing fuel into the furnace, these passageways are each closed by means of a door 30 which provided with a damper '31, this damper admitting air into the furnace. Hinged to the furnace are doors 32 which are adapted to be raised while the fire is burning but adapted to be closed down after the firing has been completed so as to prevent the admission of air. Access to the bake oven is had by means of the doors 33 Which are counter-balanced by means of weights 34 so that the doors 33 will remain in either opened or closed position and also that they can be readily operated without requiring any great amount of physical force, the oven is also provided with a door35 which permits the introduction of a light into the bake ovenduring the operationof either filling the oven or removing the baked articles therefrom and with a thermometer 36 by which the temperature of the oven can. be ascertained,

WVhen my device is used for fuel oil or the doors 32 are provided with a cut-away portion 3'? which permits a pipe 38 to pass therethrough, this pipe has attached tonne end a burner 39 which is located. in thehtur nace 11 the pipe 38 is connected to a supply pipe 40 which is carried by brackets 4-], these brackets are secured to the wall of the oven, the valve 42 is used to regulate the supply of fuel. hen either oil or gas are used, the door is eliminated and bricks 43 are used to fill in the space occupied thereby, as in this kind of firing it is not necessary that air enter into the heating furnace since all the air necessary for combustion is fed through the pipe simultaneously with the fuel;

the bricks 43 are not cemented in Jlace but placed in loosely so that they can be readily removed to get at the burner either for re pairs or lighting purposes.

While I have shown my even as being of the side firing type, I can so arrange it as to tire the same from the rear or front without departing from the spirit of my invention.

The operation of my device is as follows The doors 32 are first raised and secured in upright position in any well known manner, the doors 30 are then opened, the fuel is placed in the heating furnaces 11, the fuel is then ignited and the doors 80 closed, the

draft being regulated by the dampers 31 and 26, the fuel is now permitted to burn out completely during which operation the vari ous parts of the oven become highly heated. The dampers 31 and 26 are then closed, the damper 26 preventing the escape of the heat within the furnace and the damper 31 preventing the admission of cold air, the doors are also lowered thus assisting in preventing admission of air through the firing door, the oven is now ready for baking and the articles to be baked are inserted through the doors 33 in the usual manner.

I have found by use of my device that it is possible to use only one heating for two batches of baking, in other words, it was only necessary to fire the oven every other day and in this manner, a great deal of fuel is conserved, of course, until the even has been thoroughly heated through, it is necessary to lire every day, but after being once heated thoroughly firing every other day only, was necessary. It will be noted in my c onstruction that I have eliminated grate bars and ash pits in my furnace by making a solid floor therein, these two features assist materially in maintaining the oven temperature in that the hot ashes are held in relatively close proximity to the bottom of the oven and continue to radiate heat even after the fiames have entirely disappeared. Tn furnaces where grates are used, the hot ashes fall downward. into the ash pit and thus supply no heat to the oven and at the same time the additional openings necessary for cleaning the ash it increases the possibility of cold air entering and chilling the oven; another feature of my construction is the relatively heavy body of material under-- neath the oven floor which heated and retains the heat a great deal longer than a light construction which heats up very readily but looses the heat just as readily, and by the flue construction above the oven the formation of eddy-currents and consequent hotand cold spots on the oven roof is eliminated.

My bake oven is not designed to be a continuous firing oven, it being my intention to place a full fuel charge in the furnace and then light the fuel from the front, or in other words, at the door. In this manner a solid floor can be employed because the fire being placed at the front portion of the fuel or that portion nearest the door, the draft, which enters through the door, will carry the flames and heat backward through the whole pile of fuel, which is in the furnace and thus cause the ignition to travel from the front to the back and as the fuel burns and is reduced to ash, it will naturally sink down to the floor and permit the free passage of air for the remainder of the combustion. In this manner my furnace can be utilized either for coal, coke or wood.

It is a well known fact that in the old bakers ovens, the oven itself was filled with wood, which was ignited at the door and after the wood had been burnt out, the wood ash was removed by means of a rake and a swab, and the article to be baked inserted directly into the place where the firing had originally been placed. Coal, however, creates a certain amount of soot so that it was impossible to use coal in the same manner that wood was employed. In my device, I have supplied a furnace directly beneath the baking chamber constructed on the old style principle, that is with a solid floor and in which the firing is done in the same manner, that is the furnace is first fully charged with fuel and the ignition started at the door and after ignition is once started, no additional fuel is to be fed to the furnace; the one charge being sufficient to heat the oven to the proper temperature. In other words the combustion sweeps through the entire pile of fuel from the front to the back and thus every particle is consumed without the necessity of introducing air beneath the fuel pile. 1

Having fully described my invention, what I claim is:

A bake oven comprising acasing, heat furnaces having a solid floor located insaid becomes highly tioned fines to said chimney, means for closing off draft through said chimney, and 1 means for closing off draft through said furnaces. V

In testimony whereof, I have signed my name to this specification.

, PETER AHLHEIM. 

